Google is working on a new service that will allow you to pay your bills from directly within your Gmail email inbox, ridding of the need to visit multiple websites every time you pay your bills each month.

Recode was able to get its hands on all the details for the secret project, dubbed “Pony Express”. Internally, it’s being called “the future of paper mail” and is expected to roll out in the fourth quarter of 2015.

To get Pony Express up and running inside your Gmail when it launches, the leaked document say users will need to provide personal information including name, address, and full social security number. The data and identity verification will be handled by a third party, rather than Google itself.

According to the leaked document, Google is partnering with third-party services that print and mail out bills on behalf of service providers such as insurance companies, telecom companies and utilities. The bills will appear in your inbox and can be sorted into a separate Pony Express folder. Recode says it’s not clear if Google is also working directly with the service providers, too.

One of the coolest parts of Pony Express is the ability to share a bill with another Gmail user, which could be useful if you split, say your housing bill, with roommates.

The screenshots leaked show support for Android, though there was no mention of iOS. Google has been one of the big development firms to support iOS wholeheartedly with all of its services, so we wouldn’t be surprised to see Pony Express make its way over – at least through the new Google Inbox app already available.

So why is Google doing this? The data from Pony Express could be used to refine how advertisements are targeted to individuals.